i want to answer to that part in particular, since it seems to be a misunderstanding from your part on this (if you allows me).
" - Yoshi-P's repeated statement on accessibility to all ranges of player types "
he means there, that it will recquire nothing special or skill or time sink for get acces to something. the story quest, is not a time sink, it's the backbone of the whole game, it's can't and mustn't be ignored. it's what make this game what it is. get a level 50 and do the story quest are accessible to anybody, the only difference will be time... but we already have seen that it was not a trouble for them, with the relic quest... it's accessible, however it ask a long dedication.
" - Yoshi-P saying he felt this particular class/job was missing from the original lineup and this is why we are seeing it before the expansion. "
yes, like he feel that a two hand sword and gunner class are missing too. sadly they will not be a starting class, he was simply saying that the order of how the class will be added was look at... mostly for decide what was the most important and urgent to be added. not that it must be a starting class.
he was just saying that the game was missing this and was needed.
all of this for say, i highly doubt that any class that will come from now (exept rare exeption like class tie to a race, and even that i doubt they will do it) will be added to the roster of the starting class, they will all be unlocked through our story quest or progression in the world.
see it like this... you are beginning to your city and begin to explore the world, discovering new technique and new way to fight. that how it work...
ps; i still think that one class will maybe be added in the roster to the starting class and it will be probably the gunner class that was asked for more of 4 years now. but even this can't be sure. (it's the only other class that have a guild appearing somewhere with a sign and place already installed)